Genes & Cells

Genetics of wrinkly dogs, plus cancer killers and diabetes thwarters in this week’s news

March 18, 2011 at 4:41 pm

DNA that wrinkles dogs
A duplicated piece of DNA gives Shar-Pei dogs their wrinkles, but also causes familial Shar-Pei fever, a disease characterized by high fevers and swelling. The extra DNA, discovered by an international team of researchers, helps turn on the HAS2 gene, leading to production of hyaluronic acid. The acid builds up in the dog’s skin, causing wrinkles, and triggers the immune system to fight infections. The extra DNA is also linked to high fevers in the more wrinkly of the Shar-Pei varieties, the researchers report online March 17 in PLoS Genetics. Hyaluronic acid may also be responsible for fevers and swelling in people with similar inherited diseases. —Tina Hesman Saey

WRINKLE GENE An extra bit of DNA gives Shar-Pei dogs their wrinkles. The traditional Shar-Pei breed (far right) has a smaller piece of extra DNA than more wrinkled “meatmouth” varieties (three dogs on the left). The same DNA also leads to high fevers in the meatmouth dogs. Olsson et al/PLoS Genetics 2011

MicroRNA kills errant cancer cells
Scientists may have found a molecular bounty hunter that can kill wayward cancer cells hiding in parts of the body far from the initial tumor. A tiny snippet of RNA called microRNA-31 or miR-31 can kill breast cancer cells that have spread to the lungs. The microRNA turns off production of proteins that cells use to build skeletons and cling to each other, researchers at MIT and the Whitehead Institute in Cambridge, Mass., show in a paper published in the March 15 Genes & Development. The microRNA didn’t affect the initial tumor. Therapies that can stop cancer once it has spread may eliminate up to 90 percent of cancer deaths. —Tina Hesman Saey

Genes protect against type 1 diabetes
Two genes involved in controlling viruses may play a role in type 1 diabetes, a disorder in which the immune system kills insulin-producing cells in the pancreas. Researchers have known that infections with certain types of viruses may trigger the disease, but it wasn’t clear if the viruses kill the cells directly or if the cells are collateral damage of an overaggressive immune response. Now researchers led by Marco Colonna at Washington University in St. Louis show that two virus-sensing proteins protect against type 1 diabetes by turning on the immune response against a virus that settles in the pancreas. The study appears online March 14 in the Journal of Clinical Investigation. —Tina Hesman Saey